1. Field of the Invention
The present invention relates to a method for checking groups of data formed from a plurality of bytes according to which a characteristic check sum value is formed pursuant to a defined algorithm in a manner involving all bytes wherein the check result is obtained by checking a check sum word corresponding to the check sum value for the expected formation.
2. Description of the Prior Art
In connection with the checking of the contents of storage units of electronic modules which are described by a processor, such a check would progress such that the processor forms a check sum code word via the data delivered to the module. The module forms a check sum code word via the data stored in its storage unit and these check sum code words are compared.
If the electronic modules are a matter of modules of communications technology, then it is possible that the storage contents are intended to remain unmodified for a relatively long time in an undisturbed operation. It thus has to be permanently checked whether the stored data bytes are still contained in the original form. That is, following the initial writing-in, a check sum must be repeatedly formed by the module and compared to the originally determined check sum word in permanent fashion.
Previously, if individual bytes stored in the storage unit of the electronic module had to be modified on the basis of any sort of modification of the switching conditions, the course of action taken was to first execute a check sum formation over the entire new data stock not only by the processor but also by the module, and to then perform a check sum word comparison--as in the case of the first description.
Because of the great number of bytes to be taken into consideration in modern modules of complication technology, such check sum formations are relatively time-consuming. While this is not substantial for the modules themselves, in this context, the loading of the processor thus conditioned represents an undesirable dynamic load increase as this processor has to fulfil other tasks as well.
It is therefore an object of the present invention to propose a method for checking groups of data formed from a plurality of bytes wherein the method leads to more favorable relations in the context described above.